[A Case of Primary Omental Well-Differentiated Liposarcoma].

A 61-year-old woman was diagnosed with a low-absorption tumor measuring 17×5.5×9 cm with fat density between the stomach and transverse colon by follow-up contrast-enhanced CT after surgery for early rectal cancer. The right gastroepiploic artery and vein flowed into the tumor. The tumor demonstrated high signal intensity on contrast-enhanced T2- weighted MRI images, while the overall signal intensity being suppressed on fat-suppressed T2-weighted images. Thus, the patient was diagnosed with primary omental liposarcoma and underwent surgery. The tumor, mainly located on the right omental wall with the right gastroepiploic artery and vein as feeding vessels, was hanging caudally from the greater omentum to the anterior and posterior lobes of the transverse colon. Due to the absence of peritoneal dissemination and infiltration into the surrounding organs, the transverse mesocolon was hollowed out and the entire tumor excised. Based on the histopathological findings, the patient was diagnosed with well-differentiated liposarcoma. Surgical resection is the first-line treatment for liposarcoma, and postoperative adjuvant chemotherapy is ineffective. Since the tumor was completely resected, the patient has survived without recurrence for 2 years and 6 months after surgery.